1. Field of the Invention
The present invention relates in general to a disposable needle guide, ultrasound probe sheath and an ultrasound cable sleeve as a single unit designed for use in conjunction with a transvaginal ultrasound probe for a method of gynecologic surgery wherein fluid, tissue, and minute living organisms can be recovered from enclosed human body cavities without open surgery. Specifically, this invention is designed for use in an infertility procedure in which human eggs (ova) are retrieved transvaginally from the ovary for in vitro fertilization (IVF).
The introduction of ultrasonic equipment into the field of clinical medicine and surgery has contributed immeasurably to the physician's diagnostic and operative armamentarium. The recent addition of transvaginal ultrasound probes proved to be an invaluable aid in the performance of gynecologic procedures in general and, specifically, for in vitro fertilization (IVF) procedures. IVF involves removal of human eggs from the ovary at a precise time during the patient's menstrual cycle, transporting the eggs to a laboratory where they are artificially inseminated with the husband's spermatazoa. After 48 hours, those eggs that show definite evidence of normal fertilization (embryos) are placed into the uterine cavity of the patient through a small teflon catheter for possible implantation and pregnancy.
At the present time the most widely used method of recovering eggs from the human ovary utilized a transvaginal ultrasound probe. This procedure is considered to be an operative one because tissue is penetrated and a closed abdominal cavity is entered. Therefore, it must follow the usual guidelines of surgical sterility.
When performing transvaginal ovuum recovery procedures, the vaginal probe is fitted with a suitable sterile covering. Then, a sterile stainless steel needle guide is attached to the vaginal probe. The needle guide serves as a passageway for the introduction of an aspirating and flushing needle (or other suitable) instruments. The aspirating and flushing device disclosed in my copending application U.S. Ser. No. 135,701 filed Dec. 21, 1987, now U.S. Pat. No. 4,824,434 issued 4-25-89, and incorporated herein by reference, has been demonstrated to be ideally suited for this purpose. When the probe and guide are inserted deeply into the vaginal vault, the aspirating needle is introduced into the guide. Thereafter, when advanced, the needle need only penetrate the thin vaginal wall to gain access to the ovary located inside the abdominal cavity.
An ultrasound transducer located in the distal end of the vaginal probe makes possible the projection of a clear image of abdominal organs onto a nearby ultrasound screen. Direction and depth of the aspirating needle can be observed on the ultrasound screen and directed to the target ovarian follicle where vacuum aspiration of the egg-containing follicle is a relatively safe and simple manuver.
In experienced hands, the complication rate from this procedure is very low and, when complications are encountered, they are usually the result of either infection and/or internal bleeding induced by a misguided aspirating needle. Such complications, although relatively rare, may threaten the future reproductive capacity of the patient and prove to be quite costly in terms of patient welfare. An in-depth study of the transvaginal ultrasound equipment manufactured throughout the world, and the manner in which it is used, points out deficiencies in the prior are that favor the occurrences of the aforementioned complications that have not been fully rectified. Therefore, it is the purpose of the present invention and embodiments to effectively overcome the deficiencies existing in the prior art.
2. Description of the Prior Art
In the performance of transvaginal ultrasound probe procedures, whether diagnostic or operative, it appears that little attention is directed toward the avoidance of potential hazards of the transfer of sexually transmitted diseases (STD'S), some fatal, from one patient to another. The presence of human blood and vaginal secretion within the operative field provide a high risk environment for STD'S and requires that precautions be taken to insure that instruments that come into contact with these body fluids either be capable of adequate sterilization or discarded after each use for proper disposal. This becomes a problem when performing transvaginal operative procedures because the vaginal ultrasound probe and cable extending from it to the main ultrasound unit cannot be surgically sterilized.
As a result, many makeshift methods have evolved in an effort to provide a means whereby the transvaginal probe, needle guide and ultrasound cable can be covered with sterile material(s) enabling these items to be brought into a sterile operative area. Prior art designed for this purpose, employ a seperate covering sheath for the vaginal probe and a seperate sheath to envelope the ultrasound cable, as well as a seperate needle guide. These component parts are joined together with either sterile rubber bands or sterile adhesive tape. The sterile covering mechanism, if not of single unit construction, is a potential source for contamination of instruments, thereby creating the possibility of disease transmission.
Many clinics use a gas sterilized, commercially available condom to cover the vaginal probe in order to prevent probe contamination and provide a sterile probe surface. The practice of using a rubber condom is crude, offensive to many patients and frequently results in probe contamination due to breakage of the condom. When the probe becomes contaminated with blood and/or body fluids, cleansing is sometimes unreliable and time consuming. Some clinics use commercially available sandwich "baggies" to accomplish the same result. This too is subject to damage and contamination, as well as providing varying degrees of local discomfort to the patient.
Soaking the vaginal, probe in an, antiseptic solution prior to each use is frequently used, but is not totally effective in bringing about adequate sterilization and can prompt a local reaction or act as an irritant to delicate vaginal membranes of the patient. This practice is particularly undesirable when egg recovery procedures are performed, because of the possible toxic effect of the antiseptic solution on delicate human eggs. Moreover, prolonged soaking of the probe threatens the functional longevity of the ultrasound mechanism. In addition, soaking the probe before each use to achieve chemical sterilization requires the loss of valuable operating time.
Inasmuch as transvaginal operative procedures require maintenance of a sterile surgical area, it is necessary that the transvaginal probe handle and the ultrasound cable extending from it be covered by a sterile material. The prior art approaches this problem by providing a separate thin gauge plastic sleeve fitted over the cable and secured to the vaginal probe--again by tape or rubber bands.
Almost without exception, transvaginal ultrasound operative procedures are performed by using a reusable or permanent needle and/or instrument guide separate from the sheath covering the probe. A review of the world medical and surgical technology regarding transvaginal ultrasound probe units is presented in a special issue of CONTEMPORARY OBSTETRICS AND GYNECOLOGY, Vol. 30, Oct. 1987. Thirteen of the 14 manufacturers of ultrasonic equipment offer only the permanent or reusable guide. The reusable guide consists of a hollow stainless steel tubular design applied to the vaginal probe, either with the use of special clamps that can be secured to the probe or by fitting the guide into slots contained in the plastic probe housing.
Although the permanent needle guide can withstand surgical sterilization to permit it to be reused, there are several disadvantaged to this type of guide that far outweigh this advantage. The reusable or permanent needle guide is very costly, easily bent, and/or broken. Its practicality is severely restricted because it requires proper cleansing and sterilization after each use. When several operative procedures are scheduled in succession, either multiple needle guides are necessary or considerable valuable time is unnecessarily lost while awaiting sterilization between each procedure.
The potential for serious complications resulting from a misguided needle or instrument is great if the needle guide is not adequately secured to the vaginal probe. It is important that the needle guide, whether reusable or intended for one-time use only, be prevented from rotation or movement when positioned on the ultrasound probe. It is the needle guide that directs the position of the operative needle. If the guide becomes dislodged from the probe, needle or instrument control is lost.
I know of only one company to offer a disposal needle guide for use with their transvaginal ultrasound probe. Although the needle or instrument guide itself is disposable, the manner in which it is used in preparation of the vaginal probe for transvaginal ultrasound operative procedures is essentially the same as other prior art. It continues to use a modified sterile condom or sheath to cover the probe. A separate sterile plastic sleeve is supplied to cover the ultrasound cable.
This "snap-on" disposable needle guide is attached to the vaginal probe over the rubber probe sheath and relies only on the guide fitting into a slot provided in the vaginal probe housing. Several deficiencies are readily apparent. The cylindrical ultrasound probe shaft provides potential for lateral rotation of the "snap-on" cylindrical needle guide. Stability of the securing mechanism of the guide is open to serious question inasmuch as the rubber sheath covering the probe shaft is interposed between the needle guide and the shaft, thereby making adequate fixation difficult.
In addition, the exist portal of the needle guide is located far behind the leading surface of the transvaginal probe head. This results in an undesirably large segment of the operating needle remaining unsplinted by the guide, thereby favoring the possibility of needle breakage or bending. This often results in misdirection of the advancing needle during operative procedures. The unsplinted needle portion should be minimal in order to protect the needle and maintain a straight and predictable operative path of the needle if complications are to be avoided. Another deficiency in this art is the use of a modified condom sheath to cover the probe head and shaft. Although an improvement over the commercially available condom, it is still subject to breakage with resultant contamination.
Still another deficiency is the fact that the ultrasound cable sleeve is a separate part of the device. When preparing the transvaginal ultrasound probe for operative use, application of each separate component part requires extra time and care in order to avoid contamination of either the surgeon or the probe covering. The present invention corrects these deficiencies found in the prior art.
When the transvaginal ultrasound probe is used only for daily diagnostic examinations wherein penetration of tissue is not required, it is not essential that an elaborate sterile operative field be maintained. Nor is it essential that the ultrasound cable be shielded with a sterile cover. A needle or instrument guide is not required. The prior art continues to employ a sterile rubber condom or sterile plastic "baggie" for this purpose. Ideally, the operative sheath should be surgically sterile, easy to apply and remove, constructed of a material that eliminates breakage and contamination and designed for one-time use only. An extension of the present invention satisfies these criteria and thereby overcomes the stated deficiencies in the prior art.
To date, there are no known references in the prior art regarding a protective device to guard against accidental damage to the transvaginal probe when not in use. The transvaginal probe being constructed of plastic is subject to breakage, thereby rendering the instrument inoperable. An extension of the present invention is provided to guard against probe damage, thereby eliminating costly repairs and the loss of substantial operative use of equipment.